Many automotive interior door panels are molded to have a two-tone texture color appearance. Typically, there is a main surface covering the entire panel which is covered with a first cover of vinyl. Located within the interior of the panel is often an insert covered with an alternative color of cloth material. The cloth insert and vinyl material typically will also have underneath some type of foam or fiber padding to make the interior of the door panel soft to the touch. One method to obtain a two-tone texture color appearance is shown and described in co-pending patent application Ser. No. 08/041,109 to Stein et al, commonly assigned. The Stein et al method requires a molding operation.
An alternative to the Stein et al process which does not require a molding process is to prepare a door panel covered in vinyl and then to achieve the two-tone effect by gluing the cloth insert to the vinyl. Still another method of achieving the two-tone texture appearance is to first attach the cloth insert to a cardboard platform and then, by gluing or by some type of fasteners, attach the cloth insert to the door panel. The gluing or fastening method of attaching the cloth insert to the door panel is technically acceptable. However, from a labor standpoint, the gluing or fastening method is not desirable.
Still another process of attaching a cloth insert to a vinyl-covered interior door panel is the dielectric tear seal process. In the tear seal process, the cloth insert is positioned on the padding. The vinyl is placed over the cloth insert and the remainder of the door panel. The padding, cloth insert and vinyl are dielectrically bonded together along the edges of their interface between the cloth insert and the vinyl. At the same time that the dielectric press joins the vinyl to the cloth, the press also serrates the vinyl so that it may later be torn away, hence the term tear seal is given to the process.
The tear seal process offers four major disadvantages. The first disadvantage of the tear seal process is that two steps are involved, namely the joining of the vinyl to the cloth insert (and to its underlying padding) and a second process which requires the vinyl which had been serrated by the dielectric tool to be torn away. The above is a two-step process and requires the expense of the second operation. Additionally, the torn-away portion of the vinyl increases scrap cost and disposal cost for associated refuse.
The second disadvantage of the tear seal process is that if the serrating or tear process is not totally accurate, the door panel will have to be scrapped due to the unsightly appearance where the vinyl is torn.
Thirdly, the cutting serrations on the dielectric tool dies cause the tool to have sharp edges. The sharp edges required on this type of dielectric tool die attract the energy from the high voltage field required in the dielectric process generating sparks, thereby mandating high maintenance rams on the dielectric tools.
The fourth major disadvantage of the tear seal process is that it can only utilize an unsupported vinyl (a supported vinyl has a fabric reinforcement) since the vinyl has to stick with the cloth insert material. Therefore, the door panel does not exhibit the superior wear characteristics of a door panel that utilizes a supported vinyl.
Prior attempts to dielectrically manufacture a door panel insert with a cloth lower trim and a supported vinyl upper trim failed due to the lack of control over part alignment, adequate adhesion between the supported vinyl and the cloth insert, and the raw edge treatment to process out the exposed supported vinyl strings.